Rich voltage, poor voltage: My incandescent tale

Recently some of the incandescent bulbs in my house started burning out at a higher-than-traditional rate.

Recently some of the incandescent bulbs in my house started burning out at a higher-than-traditional rate. (Yes, we still have quite a few of them in use, in addition to CFLs and even an LED bulb.)

At first, I assumed that it was just coincidental manufacturing defects, but since the bulbs were of different wattages, and from different sources, maybe that wasn't the case. Of course, they could all be from the same factory, just with different labels and packaging.

But I have a small AC-line voltage readout in one of my outlets; it's a unit I received at least 15 years ago from Datel (now part of Murata Power Systems). Even though the date code says 1996, Datel/Murata still lists it on their web site, here. It's a tribute to the longevity of its seven-segment LED display that it is still readable, though the segments have dimmed and their uniformity is not as good as when I got it (see photo) - but hey, this is 24/7 operation over all those years, so we're talking 130,000+ hours, thus far.